High temperature lubricant



Patented Apr. 11, 1944 2,346,357 I men TEMPERATURE nunrucam Robert E. Burk and Everett 0. Hughes, Cleveland Heights, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio, a corporation of o No Drawing. Application December 24, 1941,

Serial No. 424,362

4 Claims.

This invention relates to lubricants; and it is among the objects of the invention to provide improved lubrication in high temperature, such as in internal combustion engines. Other objects and advantages -will appear as the description proceeds.

To the accomplishment of the foregoing and rehaving oxidation activity or which are oxidation catalysts not particularly at crank-case tempera may be used. There is a distinction in favor of the chromium compounds over the others, and particularly cobalt. A chromium salt or naphthenate, is especially characterized by catalyzing the combustionand elimination of carbonaceous deposits at combustion zone temperatures, while inhibiting deterioration of oil at crank-case temperatures in the presence of iron and copper. The other naphthenates or salts have a tendency to also promote the oxidation or deterioration of oil at crank-case temperatures in the presence of iron and copper, and cannot be advantageously used alone in oil as in the case of the chromium compounds, but they require further corrective additions. The chromium compounds also may be used with the said anti-oxidant agents. These agents comprise: nitrogen-containing diphenyl methane derivatives, i. e., tetramethyl diamino ture but at higher temperature, promote diminution of carbonaceous deposits outstandingly, and in combination with what we term an "antioxidan give results much better than the total of the respective agents alone, anti-oxidant? here having a meaning not as with gasoline but as an inhibitor for metal catalysts such as iron,copper, or lead. It is particularly remarkable that an agent of oxidizing character and whose activity tends primarily to be antagonistic to anti-oxidant action should work to these ends. The salts of metals constituting the oxidation catalysts comprise: naphthenates; salts of acid radicals such as of tall oil or sulphurized tall oil; acids derived from the oxidation of petroleum fractions or polymers; xanthic, i. e., acids of the type of carbonaceous'deposits. The naphthenates may also'be chlorinated or halogenated, and in some cases sulphurized. ,The metals above referred to are chromium, also vanadium, manganese, cobalt and molybdenum. In general. 96 to 2 per cent, or

more, up to 8 per cent oi the metaicompounu 65 diphenyl methane, diamino diphenyl methane. and analogues, also sulphur-containingcom pounds such as P28 treated degras, PzSs treated polyoleflns, P285 treated distilled cashew nutshell oil, etc. Up to 3 per cent, preferably /4 to 2 per cent of such agent additive to the metal compounds may be employed. Particularly the va- 'bustion zone temperature, but a further peculiarity is that the latter property is destroyed by the sulphur-containing additives except with the chromium salt. Further, the corrosive tendencies of the metal naphthenates, particularly of cobalt, vanadium and manganese, toward bearing metals and copper is reduced by tetramethyl diamino diphenyl methane, and peculiarly it is found to be completely eliminated by the further inclusion of less than /4 Per cent of diamino diphenyl methane.

As an example: A lubricant is made up 0! S. A. E. 20 lubricating oil and 0.5 per cent of chromium naphthenate and 1.5 per cent of the reaction product of Pass on degras.

As another example: A lubricant is made up of a similar on and 0.5 per cent of cobalt naphthanate and 1.5 per cent of tetramethyl diamino diphenyl methane.

As another example: A lubricant is made up with a similar oil and 0.5 per cent of chromium naphthenate and 2 per cent of the reaction prode uct oi Pass on polyoleiin.

As another example: With a similar lubricating oil there is incorporated chromium naphthenate V per cent and tetramethyl diamino diphenyi methane %-2 per cent.

As another example: With a similar lubricating 011 there is incorporated vanadyl naphthenate /z percent and tetramethyl diamino diphenyl methane -2 per cent, and diamino diphenyl methane 0.15 per cent.

As another example: With a similar lubricatin oil there is incorporated cobalt naphthenate /2 per cent and tetramethyl diamino diphenyl methane -2 per cent and diamino diphenyl methane 0.15 per cent.

As another example: With a similar lubricating oil there is incorporated per cent of manganese naphthenate and -2 per cent of tetramethyl diamino diphenyl methane.

As illustrating the properties of such lubricants, the following test-results are noted in summary, in which E is bad or worse than the oil alone, i, e., over 30 mg. of lacquer and over 7 per cent of carbon residue, C is mediocre, i e., 10-30 mg. of lacquer, and 3.0-7.0 per cent carbon residue, and A is excellent, 1. e., less than 10 mg. or lacquer and less than 3.0 per cent ofbarbon residue.

The carbon residue is determined by exposing a 2.5 g. sample or the lubricant in a '70 mm. diameter Petri glass dish in an electric furnace for'16 hours at 525 F., followed by 6 /2 hours at 750 F. The carbon suspension is determined by suspending /2 per-cent by volume of carbon in the lubricant, and a 100 cc. sample of the suspension in a 100 cc. graduate i set in an oven at 200 F., and the number of cc. of clear oil is measured at intervals. The oxidation and lacquer is determined by exposing the lubricant in the presence of metals, iron and copper, at a temperature of 310 I". ior.65 hours by blowing air through at the rate of 30 liters per hour.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the iollowing claims, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as our invention:

1. A lubricant promoting combustion of deposits case, which comprises a lubricating oil and up to a about three per cent of a salt of an organic acid of low volatility the stated salts or which promote diminution of carbonaceous deposits and a metal having oxidation activity from the class consisting of vanadium, chromium, molybdenum, manganese and cobalt, with a complex organic acid. and a diamino diphenyl methane derivative.

3. A process of promoting combustion of deposits in the combustion zone of internal combustion engines and producing high stability in the crank-case, which comprises subjecting oil to internal combustion engine temperature in the presence of up to about three per cent each of a salt of metal having oxidation activity from the class consisting of vanadium, chromium, molybdenum, manganese and cobalt with an organic acid of low volatility the stated salts of which promote diminution of carbonaceous deposits. and 

